Air brush



Feb. 26, 1929. 1,703,219

' O. C. WOLD AIR BRUSH Filed April 11, 1927 2 Sheets-Sheet l 0. C. WOLD AIR BRUSH Feb 26, 1929.

Filed April 11, 1927 2 Sheets-Sheet 2 9 a v a. j j M W M W a 6 .fl. j J W M y J J Y J Mm r 4 .y W M .J w W m W HZ" 1. 0 6 7 f. W r T M fl a 7 n 56 a V Z 7 W v Nfilli 111111 1 1 1 2 1.1:- 1| \|||\|||1||1\:L f W 1 ill 1 l \l\111l\\ a i Z 6 r 5% w W Patented Feb. 26, 1929.

UNITED, STATES 1,703,219 PATENT OFFICE.

OLAUS C. WOLD', OF CHICAGO, ILLINOIS.

AIR BRUSH.

Application filed April 11, 1927. Serial No. 182,747.

lates to the means provided for controlling a supplemental discharge of air from points laterally adjacent to the centrally disposed pigment outlet, so that, if desired, the form of the spray jet may be flattened out, and the planeof discharge regulated as occasion may require. This permits thebrush to be used in the discharge'of a truly conical jet or of a flattened fan shaped jet, as may be desirable forthe work in hand.

The invention further relates to the arrangement and mounting for the trigger which operates by a straight line movement, to first open the air discharge, and by continued movement to open the pigment discharge, which method of mounting and moving-the trigger is superior tothe pivotal arrangement for the trigger commonly employed in devices of this character. i

The invention further relates to the construction and method of adjustment of the nozzle head which provides the supplemental air passages for flattening the spray;

. to the means for constructing and mounting the pigment receptacle; to the means for securing the air pipe which supplies air under pressure to the brush, and to the general construction and arrangement of the brush as a whole and the individual parts thereof.

In the drawings:

Figure 1 is a side elevation of the air brush of the present invention;

Fig. 2 is a longitudinal sectional elevation of the same; and

Fig. 3 is a detail elevation "at right angles to that of Fig. 1 showing in detail the means for. securing the pigment can to the barrel of the brush.

The brush as a whole comprises a tubular barrel which is closed at its rear'end by a breach plug 11, provided through its center with a longitudinal bore 12 which opens forwardly into a main chamber 13, the wall of the chamber being provided'in its base with an elongated slot 14: which affords a clearance for the back and forth straight line movements of a trigger 15 adapted to be retracted by the first finger of the operator. The rear end of the breech bore 12 is closed by a threaded plug 16 having formed therethrough a bore 17 centrally aligned with the bore 12, but of less diameter than said bore. The plug 16 has threaded thereon an adjustable end cap 18 adapted to be turned back and forth to regulate the distance between the end of the plug 16 and the end 19 of the cap.

The barrel at its forward end is closed by means of a head plug 20, cored to provide a central pigment chamber 21 on the rear side of which is located a bushing 22 threaded into the head plug and provided with a cen tral bore 23 aligned with the bore 17 in the rearplug 16, and these two bores, in unison, furnish guideways for the reciprocation of a needle valve 24, the bushing 22 being provided to permit easy substitution of parts in case of wear. The needleivalve 24 extends through and beyond the pigment chamber 21 and through a tapering pigment nozzle 25, the rear end of which is threaded into the head plug 20.

The nozzle 25 is provided with a bore 26 of larger diameter than the needle, which bore at its forward end is tapered down to a diameter substantially equal to the body diameter of the needle, which latter is tapered at its tip end 27 which, when closed, protrudes outwardly from the tapering nozzle 26, but which may be retracted to afford an annular outlet for the discharge of pigment around the tip end of the needle.

The head plug 20 is exteriorly threaded at its forward end 28 to receive a cap 29 which surrounds the tapering nozzle and is provided in advance of the plug 20 with a forwardly tapering air chamber 30 which is closed at its front end by the front wall 31 of the cap. The wall of the air chamber 30 on one side is bored and threaded to receive an adjusting valve stem 32 carrying at its inner end a conical valve 33 which bears against a beveled seat 34. When the valve is adjusted inwardly communication is established from the air chamber 30 to an air port 35 extending through the front wall of the cap 29. i

The front or outer face of the cap is provided with a centrally disposed boss 36 which surrounds the nozzle 25, and around this boss is fitted a rotatable collar 37, having on its inner face an annular recess 38 which, in conjunction with the front face of the cap 29, affords an annular chamber for the passage of air admitted through the port 35. The collar 37 is provided with two oppositely disposed air discharge ports 39 which converge forwardly toward one another, and toward therjet of pigment ejected from the nozzle, the'arrangement being such that the impingement/of the inwardly converging streams of air from the discharge ports 39 will cause a flattening or spreading of the pigment spray.

The forward inner face 40 of the collar is outwardly flared or beveled from the margin of the boss 36 to avoid interference with the flaring or diverging spray ejected from the nozzle, the collar is held in contact with the cap 29 by the provision of a-coupling ring 41 which is threaded onto the forward end of the cap 29 and overhangs a marginal flange 42 formed around the inner face of the collar. A port 43 affords communication between the chamber 30, and an annular chamber 44, so that air admitted'to the latter chamber will find egress in part through the annular space around the centrally disposed pigment nozzle and in part through the laterally disposed converging discharge ports 39.

The breech plug 11, near itsxforward end, is provided with an annular chamber 44 which communicates on its lower side with a laterally opening air passage 45, which in turn communicates with a bore 46 in an air valve housing 47, of cylindrical formation,

which lies below the breech plug and extends in parallel relation to the rear end of the barrel. The annular chamber 44 is also in communication with the chamber 30 through an air tube 44 which communicates with the annular chamber 44 into which the passage 43 enters. a

The bore 46 merges into a guide bore 48 of reduced diameter which affords a mounting for an air valve stem 49, which projects forwardly and maintains contact with the rear face of the trigger 15. The valve stem 49 extends through the bore 46 and carries a conical valve plug 50 which lies within a valve chamber 51 of larger diameter than the bore 46, the conical valve seating against the shoulder formed at the rear end of the bore 46. The rear end of the valve stem 49 is surrounded by a coil spring 52, which is housed within a chamber 53 formed in a spring housing 54 which is threaded into and extends rearwardly from and in continuation of the valve housing 47. The spring serves to impart a forward thrust to the valve stem in order to maintain contact with the trigger and to restore the valve to closed relation when the trigger is;- released.

The chamber 51 is provided in its lower side with an air inlet port 55 which communicates with the interior of a pistol grip handle 56, which is connected with the breech plug by a neck 57 through which the valve housing extends. pistol grip handle is provided with a threaded nipple 58 terminating in a tapered unthreaded tip59 which is surrounded by the valve 24, and behind the head block theneedle carries a rigidly mounted, collar 64, which normally stands in spaced relation to the rear face of the head block, which latter slides freely upon the needle as a guide. After clearance has been taken up between The lower end of the the head block and the collar, the continued movement of the head block will cause a retraction of the needle and an opening for the discharge of pigment.

In order to normally maintain the needle in advanced relation, a coil spring 65 is pro vided which encircles the needle and, at its forward end, bears against the collar 64, and

at its rear end against the plug 16, and by.

adjusting the position of the cap 18, the range of movement of the needle can be regulated.

The head plug 20 has depending therefrom a neck 66 which is threaded at its lower end to receive the upper end of a tubular boss 67 which extends upwardly from the center of a rimmed cap 68 which constitutes the closure for a cylindrical can or cup 69 for the reception of the pigment. The boss 67 is interiorly threaded to receive the upper end of a pigment supply tube 70 which extends down to a point in close proximity to the base of the can or cup, which arrangement of parts affords a passage for the pigment from the can or cup upwardly through the boss and neck 67 to the chamber 21. The rim of the cap 68 is of a size to afford a close sliding lit around the upper margin of the can or cup, and special means are provided for holding the parts in sealed relation to one another.

The boss 67 is encircled by a collar 71 .which is chambered out at 72 to afford a housing for a coil spring 73 which bears against the upper surface of the cap 68. The collar 71 is provided with oppositely disposed laterally extending arms 74, to the ends of which are rigidly secured a pair of hangers 7 5 which lie outside of and depend 'below the rim of the cap 68.

. Each of the hangers is provided in its edge with a slot 76, and the slots are positioned to engage with a pair of oppositely disposed studs 77 on the can or cup,

the positioning of the parts being such that as the can or cup is rotated to secure engagement of the studs with the slots, the hangers and the collar 71 which carries them, will be dra wn downwardly against the tension of the spring 73, so that the upper rim of the can 69 will be held tightly against the underface of the cap 68, thereby sealing the connection against the accidental escape of paint or pigment.

In order to maintain the collar 71 while under spring tension in position to permit engagement of the stud 77 with the slot 76, the collar is provided on one side with a boss 78 which receives the upperend of a headed screw 79, the shank of which passes through an'aperture 80 in the wall of the cap 68. The enlarged head 81 of the screw serves as a stop to limit the upward movement of the collar 71 when the can or cup is removed, and, at the same time, the arrangement is such that when the cup or can is in place, the head 81 will be slightly depressed below the aperture 80, so that an annular duct will beafforded for the entrance of atmospheric air into the interior of the can or cup, which is necessary in order to avoid the creation of a Vacuum in the can or cup as the contents are discharged.

In operation, the pigment can is secured in place by a slight rotative movement which draws down the hangers 75 during the act of forcing the studs77 into the slots 76, so that a tight fitwill be effected. When the brush is ready for use, an initial retraction of the trigger will 'first of all retract the stem ofthe air valve, and thus admit compressed air through the air passages 45, 44 44, 44, 43 and 30 to the tip of the nozzle in preparation for the discharge of the pigment.

If it is desired to supplement the central discharge of air in order to modify or flatten the jet, the valve screw 32 is adjusted to open air communication through the laterally converging discharge ports 39. The continued straight line retraction of the triggervwill bring the head 63 into contact with the collar 64, so that thereafter an additional movement of the trigger will retract the needle valve and open the nozzle for the discharge of pigment.

The volume of the discharge can be regulated by the extent of movement of the needle valve, but by adjusting the threaded cap 18, the range of movement of the needle can be limited, so-that the maximum discharge of pigment can thus be regulated, if desired. The plane of the discharge from the supplemental ports 39 can be regulated,

as desired, by turning theflared collar 37 to bring the supplemental discharge ports into any desired position which enables the operator to secure the desired plane of dis charge without tipping or tilting the brushwhich may thus be held in upright position atall tim The mounting and method for operating the trigger is extremely simple, and, at the same time, the straight line of movement affords a much easier movement for the operators finger than that afforded by a pivoted trigger and enables better control to be maintained, and at the same time, obviates the necessity for providing any form of special mounting for the trigger which is guided and controlled by its contact with the needle valve in conjunction with its contact with the edges of the slot 14, so that other guiding and connecting means are not necessary.

The trigger will be held forwardly under spring tension at all times by the tension of the spring which seats the air valve, and the initial retraction of the trigger will be resisted only by this spring, but as soon as contact with the collar 64 has been established, the increased resistance to retraction will indicate to the operator that the needle valve is beginning to retract, so that the feel of the trigger will instantly appraise the experienced operator concerning the adjustment of the working parts within the brush. The arrangement furthermore is one which is extremely easy to assemble, since the insertion of the needle and air valve stem, with the screw plugs which hold them in position, establish the working relationship for the parts, so that extreme simplicity in construction is one of the features of the present invention.

Although the air brush 'has been described in detail, it is not the intention to limit the invention to the precise construction shown, since modifications thereof may be made without departing from the spirit of the invention. v

I claim: 1. In an air brush, the combination of a barrel provided at its forward end with a nozzle and also provided with a forwardly opening air passage in co-acting relation with the nozzle, means for supplying a liquid to the nozzle, a slidably mounted needle valve positioned to control the discharge of liquid through thenozzle, an air valve below the needle valve for controlling the passage of air through the air passage, and a slidably mounted trigger slidably mounted on and guided upon said needle valve and having a straight line movement of reciprocation and posltioned to actuate the air valve and the needle valve, substantially. as described.

2. In an air brush, the combination of a barrel provided at its forward end with a nozzle and also provided with a forwardly openin air, passage in co-acting relation ,with t e nozzle, means for supplying aliquid to the nozzle, a slidably mounted nee dle valvepositioned to control the discharge of liquid through the nozzle, an air valve below the needle valve for controlling the passage of air through the air passage, and a slidably mounted trigger guided upon said needle valve and having a straight line movement of reciprocation and positioned to actuate the air valve and the needle valve in timed succession to preliminarily effect pable of reciprocation in parallel relation to the needle valve and in position to first engage and open the air valve and subsequently engage and open the needle valve, substan tially as described.

4. In an air brush, the combination of a barrel provided at itsforward end with a nozzle and also provided with a forwardly opening air passage .in co-acting relation with the nozzle, means for supplying a liquid to the nozzle, a slidably mounted needle valve positioned to control the discharge of liquid through the nozzle, an air valve below the needle valve for controlling the pas sage of air. through the air passage, a trigger slidably mounted upon and guided by the needle valve and .in position when drawn back to preliminarily open the air valve and subsequently engagecwith the needle valve to open the same, and" springs bearing respectively against the needle valve and the air valve for normally holding said valves in closed relation and for resisting the retraction of the trigger and restoring the I same when released, substantially as described.

5. In an air brush, the combination of a barrel provided at its forward end with a nozzle and also provided with a forwardly opening air passage in co-acting relation with the nozzle, means for supplying a liquid to the nozzle, a slidably mounted needle valve positioned to control'the discharge of liquid through the nozzle, an air valve below the needle valve for controlling the passage of air through the air passage, a trigger slidably mounted upon and guided by the needle valve and in position when drawn back to preliminarily open the air valve and subsequently engage with the me dle valve to open the same, and a pistol grip handle extending downwardly in angular relation to the barrel and at a point to the rear of and below the trigger, substantially as described. a

6. In an air brush, the combination of a barrel provided at its forward end with a tapered nozzle and further provided with air and liquid passagesleading to said noz- N zle, a slidably mounted needle valve entered through said nozzle for controlling the discharge therefrom, a spring for'normally holding said needle valve in closing relation to said nozzle, a reciprocating trigger slidably mounted on and guided by said needle valve, an abutment on the needle valve for limiting the sliding movement of the trigger thereon, an air valve located below the needle valve and provided with a forwardly projecting stem engaging said trigger and adapted to be forced back bythe retraction of said trigger, a spring for moving the air valve and stem in advanced relation to close said air valve, and an air duct for supplying air to said air valve, the a trigger havlng a range of movement sufficient to first open the air valve, and by continued movement to retract the needle valve,

substantially as described.

OLAUS O. WOLD, 

